Apparatus for extinguishing engine exhaust gas sparks



P. H. SCHWEITZER ET AL 2,822,886

APPARATUS FOR EXTINGUISHING ENGINE EXHAUST GAS SPARKS Feb. 11, 1958 Filed July so, 1954 TIAHLVA I IN VEN TORS. Pea/L H.\Sc

HWEI

Pads ms.

APPARATUS FOR EXTIN GUISHIN G ENGINE EXHAUST GAS SPARKS Paul H. Schweitzer, State College, and Albrecht W. Hussmann, Centre Hall, Pa., assignors, by mesne assignments, to the United States of America Application July 30, 1954, Serial No. 446,774 Claims. (Cl. 183-32) This invention relates to extinguishing sparks carried in the exhaust gases of internal combustion engines.

Various kinds of spark arrestors or eliminators for internal combustion engines have been proposed and tried, but for certain applications none of them have proved entirely satisfactory. Thus, where fork lift trucks and the like are used in areas, such as warehouses, where highly inflammable or explosive material is stored, it is important to prevent any sparks from the truck engines from reaching the surrounding atmosphere and possibly causing a fire or explosion. At the same time, apparatus for this purpose should be simple in construction, inexpensive, rugged, dependable and not require water or other cooling liquid for its operation. Where it has been attempted to arrest or collect the sparks with dry materials, it has been found either that some of the sparks escape or that the filtering material that is used to stop them becomes clogged all too soon and must be cleaned or replaced much too frequently to be practicable.

It is among the objects of this invention to provide an apparatus for getting rid of sparks which is dependable, which is very slow to clog or foul, which is inexpensive, which requires practically no maintenance, which does not create objectionable back pressure, and which does not require any liquid or movable parts.

In accordance with this. invention, the exhaust gases of an internal combustion engine and the sparks carried by them are, passed through the tortuous passages in a mass of material that is permeable to sparks. The material used preferably consists of small pieces of metal. Air from the surrounding atmosphere also is passed through, the permeable; mass in order to maintain the material relatively coolso that the sparks will be cooled by it, as they pass through. the mass and repeatedly engage its various; surfaces. To keep larger particles or sparks from being collected in the permeable mass and soon clogging thev passages throughit, it is preferred to impart a whirling motion to the stream of gases before they reachv that material. This whirling motion causes theheavier sparks to. be thrown outward by centrifugal force. These sparks are, collected in a suitable container that can be emptied periodically, without any trouble.

The preferred embodiment of the invention is illustrated in the accompanying; drawings, in which- Fig. 1 is a front view of our spark extinguisher with part-of the air duct broken away; 4

Fig. 2 is a horizontal'section taken on the line'IIII of-Fig. 1;

Fig. 3 is a ver tical section taken on the line,IIIIII ofFig. 2;

Fig. 4 is an enlarged fragmentary vertical section through the permeable mass of spark-cooling material; and

Fig. 5 is an enlarged perspective view of one of the pieces of metal that may be used in forming the cooling material.

Referring to the drawings, a spark receiver is formed from a cylindrical housing 1, the upper part of which is cut away for most of its length. Extending through one of the closed ends of the housing is a conduit 2 that is adapted to be connected to the exhaust pipe or mufiler of an internal combustion engine. Inside of the housing the conduit preferably is concentric with the housing and extends lengthwise of it to a point a few inches from its opposite end. The open end portion of the conduit is supported by a vertical plate 3 that forms a partition in. the lower half of the housing. An arcuate plate 4 supports the central part of the conduit and likewise forms a partition in the lower half of the housing. The spaces on the opposite sides of the conduit between the upper edges of the two plates are closed by cover plates 6 welded in place. On the other side of the central vertical plate 4, most of the lower half of the housing is cut away to provide an outlet opening 7. Consequently, exhaust gases entering the outer end of conduit 2 pass through it and out of its inner end and then flow back around the upper half of the conduit until the center partition is passed, whereupon the gases flow down and out through the outlet.

it is desirable, for reasons that will appear soon, to separate as many sparks and other particles from the exhaust gases as possible by inertia; Accordingly, mounted in the inner end portion of the conduit 2 is a device for imparting a whirling motion to the stream of gases so that sparks and the like will be thrown outward by centrifugal force. This device includes an axial spindle 9- around which are wrapped several helical vanes it? that extend out to the wall of the conduit. The front ends of the vanes are secured in a ring 11 rigidly mounted on the conduit. The stream of exhaust gases is caused by these vanes to whirl around the spindle and throw the heavier sparks out against its side wall. Most of these sparks settle to the bottom of the conduit and fall through slots 12 into the space below it between partition plates 3 and 4. That space can be cleaned out occasionally by removing a clean-out door 13 from the bottom of the housing; Any sparks that fall into the space between the end of the conduit and the adjacent end of the housing through the same door.

Since it is not possible to remove the finer and lighter weight sparks by inertia in the manner just described, provision is made for eliminating those remaining in the exhaust gases after they have leftthe central conduit. This elimination is accomplished by cooling or extinguishing the sparks so that they become nonincandescent particles which are harmlessafter they leave the housing. To

cool the sparks below incandescence, they are passed through a mass of material 15 (Fig. 4) that is permeable to sparks but that requires them to travel in tortuous paths so that they will be broughtinto intimate contact with many parts of the mass. This cooling material covers the outlet 7 of the spark receiver housing. It is packed be tween wire screens 16 and 17 or perforated metal sheets likewise can be removed which hold it against the housing around the outlet. As shown in Fig. 5, the cooling material may be formed from small, curved, perforated pieces 18 of metal, although glass or other materials in other shapes could be used. The largest dimension of the pieces is preferably in the neighborhood of one-half inch. The pieces 18 forming the permeable mass are of such size and shape that the interstices between them will not be small enough to filter out the sparks and thereby prevent the cooled sparks from passing through the material and leaving the housing. On the other hand, the pieces should be small enough and close enough together to provide a multitude of tortuous passages that willcause any given spark to strike many of the pieces on its way through the permeable mass. This engagement of the sparks with the cooling material will reduce their temperature so that they will lose their incandescence and become harmless;

However, as the cooling material may be increased in temperature by the hot gases and many sparks passing through it, it is desirable to remove the heat continuously so that a low enough temperature will be preserved. This is done by passing air through the permeable mass along with the exhaust gases and sparks. The air will not cool the sparks directly very much, because heat transfer from sparks to air is slow. On the other hand, the air will maintain the permeable material relatively cool and the heat transfer from the sparks to the solid material is fairly rapid. The result is that by the time the sparks leave the outlet of the housing they no longer are true sparks but merely warm particles of carbon and the like.

The cooling air for the permeable mass is introduced into the spark-receiving housing through the opening in its top. This opening preferably is covered by an air duct 21 that has an inlet 22 in its rear face. With internal combustion engines which have a cooling fan for forcing air outward through a radiator, the air duct can be mounted with its inlet against the outside of the lower part of the radiator so that the air from the fan will enter the duct'and pass down through the spark-receiving housing and out through its outlet 7. The cooling air mixes with the exhaust gases and sparks after they have emerged from conduit 2, so the air is not heated by the larger sparks that were thrown out of the gas stream in the conduit.

With this apparatus no incandescent sparks will escape from the spark receiver, but the permeable mass in its outlet will not become clogged with particles of carbon and the like for a long time, because the larger particles are removed by inertia separation before they reach the outlet. The permeable mass does not act as a filter to stop the finer particles, but allows them to pass through it. In doing so, they are reduced in temperature to below the danger point. Our spark extinguisher is relatively simple and inexpensive, and it has the great advantage of freedom from moving parts and liquid filtering material.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

l. A device for extinguishing sparks entrained in exhaust gases from internal combustion engines comprising a container, a conduit within said container having an inlet end projecting externally beyond an end wall of said container, and an outlet end opening within said container. bafile means supporting said conduit internally of said container in spaced relation to the walls thereof, deflecting means mounted within said conduit adjacent the outlet end thereof, longitudinal openings in said conduit between said deflecting means and said outlet end and opening into said container, at first opening in said container ad- '4 jacent the inlet end of said conduit, permeable filter mean covering said first opening and a second opening in said container opposite said first opening for admitting external air into said container which exhausts through said permeable filter means and said first opening to cool said filter means whereby exhaust gases carrying incandescent particles are whirled by said deflecting means on passing through said conduit causing large incandescent particles to pass through said longitudinal openings into said container and small incandescent particles entrained in the exhaust gases issuing from said conduit to be directed by said bafile means to travel within said container and be cooled by said air cooled filter means permitting incandescent particles entrained in exhaust gas to be discharged to the atmosphere in an extinguished condition.

2. A device for extinguishing sparks entrained in exhaust gases from internal combustion engines comprising an elongated container, a conduit extending substantially the length of said container and having an inlet projecting beyond a first end wall of said container, said conduit having an expanded portion within said container terminating in an outlet adjacent a second end wall of said container, bafile means supporting said conduit internally of said container in spaced relation to the walls thereof, deflecting means mounted within said conduit in the expanded portion thereof, a plurality of openings extending longitudinally of said conduit adjacent said out let, a. removable cover carried by said container directly beneath saidplurality of openings permitting access to the interior of said container, a first opening in said container adjacent the inlet of said conduit, permeable filter means covering said first opening and a second opening in said container opposite said first opening for admitting external air into said container which exhausts through said permeable filter means and said first opening to cool said filter means whereby exhaust gases carrying incandescent particles are whirled by said deflecting means on passing through said conduit causing large incandescent particles to pass through said plurality of longitudinal openings into said container and small incandescent particles entrained inthe exhaust gases issuing from said conduit to be directed by said bafile means to travel within said container and be cooled by said air cooled filter means permitting incandescent particles entrained in the exhaust gases to be discharged to the atmosphere in an extinguished condition.

3. A device for extinguishing sparks entrained in exhaust gases from internal combustion engines comprising a cylindrical housing, a conduit extending substantially the length of said housing and having an inlet projecting beyond a first end Wall of said housing, said conduit having an expanded portion within said housing terminating in an outlet adjacent a second end wall of said housing, baffle means supporting said conduit internally ofsaid housing in spaced relation to the walls thereof, helical vanes fixedly supported within the expanded portion of said conduit, a plurality of openings extending longitudinally of said conduit adjacent said outlet, a removable cover carried by said housing directly beneath said plurality of openings permitting access to the interior of said container, a first opening in said housing adjacent the inlet of said conduit, permeable filter means covering said first opening, a second opening in said housing opposite said first opening, a duct communicating with said second opening for directing external air into said container and through said permeable filter means and said first opening to cool said filter means whereby exhaust gases carrying incandescent particles are whirled by said helical, vanes on passing through said conduit causing large incandescent particles to pass through said plurality of longitudinal openings into said housing and small incandescent particles entrained in the exhaust gases issuing from said conduit to be directed by said baffle means to travel within said container and be cooled by said air 5 cooled filter means permitting incandescent particles entrained in the exhaust gases to be discharged to the atmosphere in an extinguished condition.

4. A device as recited in claim 3 wherein said permeable filter means comprises mutually spaced screen mem- 5 bers enclosing a permeable mass of fragments of heatabsorbing material providing tortuous passages through said permeable mass.

5. A device as recited in claim 3 wherein said gas permeable filter means comprises mutually spaced screen 10 members enclosing a permeable mass of arcuately shaped perforated metal fragments.

References Cited in the file of this patent UNITED STATES PATENTS Sicka Apr. 18, 1911 Vadner Feb. 3, 1914 Markels June 9, 1936 Henry Apr. 20, 1937 Arms Aug. 14, 1945 FOREIGN PATENTS Great Britain Feb. 24, 1909 

